NEET Physics - MCQ Practice Questions

# Microscope Magnification Solution

The magnification of a microscope depends on the focal lengths of its lenses and the tube length, following the standard formula for compound microscopes.

Step 1: Identify the Magnification Formula

For a compound microscope, the total magnification is the product of objective magnification and eyepiece magnification.

where the tube length $L=v_o+u_e$ (approximately), $D$ = distance of distinct vision = 25 cm, and $f_e$ = focal length of eyepiece.

Step 2: Use the Standard Microscope Formula

For a microscope with tube length $L$, objective focal length $f_o$, and eyepiece focal length $f_e$, the magnification is:

Substituting the given values: $L=40$ cm, $f_o=2$ cm, $f_e=4$ cm, $D=25$ cm:

The magnification of the microscope is 125.

Answer: (B) 125